Hello, I've been creating a page in php that needs to invoke heavy calculation functions for which I've created dinamic extensions for linux (.so) in c++, but there's one problem I have in one of those functions, I need to modify an array passed to that function by reference and simply return true on it.
I've tried in different ways that I've found on the web, but nothing works.
Actually it does not compile, and I have no idea of how to modify that array within that function.

If somebody can give me a hand I'd really appreciate it.

Please post your code so that we can render our help more effectively.

And btw as far as my knowledge goes, arrays are by default passed by reference in C / C++, keeping in mind that passing a huge chunk of data strucutre (array) can result in a greater overhead.

Still post your code and then we will see...

I suspect the problem is in the PHP code -- I don't know the first thing about PHP. But in C or C++ passing arrays is very common thing to do. Does php duplicate the array before passing it to c/c++ then toss it into the bit bucket after the c++ function returns to php ? From your description it sounds like that is what is happening. Maybe you need to pose this question on the PHP board, not the c/c++ board.

ok, you're right I must post some code, this is what I have:

I need to pass this code from a regular c++ code to a php invoked .so library, this is the original code, which I need to translate in order to make my .so extension:

bool _stdcall Gauss(int n,double *mat, double *x)
{
    int i,j,z;
    double aux, pivote;

    for (i=0;i<n;++i){
        pivote = mat[i*(1+n) + i];
        for (j=i;j<n+1;++j)
            mat[i*(1 + n) + j] = mat[i*(1 + n) + j] / pivote;
        for (z=0;z<n;++z){
            if (z!=i){
                aux = mat[z*(1+n) + i];
                for (j=i;j<n+1;++j)
                    mat[z*(1+n) + j] =  mat[z*(1+n) + j] - (aux * mat[i*(1+n) + j]);
            }
        }
    }
    for (i=0;i<n;++i){
        x[i] = mat[i*(1+n) + n]; 
    }
    return true;
}

this was created for a windows dll but the application needs to be migrated to lunux, this should be, as far as I know the format to pass that function to a linux dinamic library:

#include "/usr/local/src/php-5.1.6/main/php.h"

PHP_FUNCTION(test);

static function_entry firstmod_functions[] = {
    PHP_FE(test,NULL)
    {NULL, NULL, NULL}
};

/* compiled module information */
zend_module_entry firstmod_module_entry = {
    #if ZEND_MODULE_API_NO >= 20010901
    STANDARD_MODULE_HEADER,
    #endif
    "test", // Extension name
    firstmod_functions,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    #if ZEND_MODULE_API_NO >= 20010901
    "0.1",
    #endif
    STANDARD_MODULE_PROPERTIES
};

ZEND_GET_MODULE(firstmod)

PHP_FUNCTION(test){
    zval *mat
  

    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a", &mat) == FAILURE) {
        RETURN_STRING("No sirve con arrya",1);
    }
    
    else{ 
        // do whatever I must do with the array, and here's where my problem is
     RETURN_STRING("funciona con array",1);
    }
}

I hope I made myself clear enough, and pardon my english I'm actually not from the states or anywhere near any english speaking country.

Looks like some form of gaussian elimination to me. Can't you just translate the c code to php cos it'll be easier to work just in php.

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